Question:Define strong number. 

A number is called strong number if sum of the factorial of its digit is equal to number itself. For example: 145 since
1! + 4! + 5! = 1 + 24 + 120 = 145

Question:What is Fibonacci series? 

We assume first two Fibonacci are 0 and 1
A series of numbers in which each sequent number is sum of its two previous numbers is known as Fibonacci series and each numbers are called Fibonacci numbers. So Fibonacci numbers isAlgorithm for Fibonacci series
Fn = Fn-2 + Fn-1Example of Fibonacci series:
0 , 1 ,1 , 2 , 3 , 5 , 8 , 13 , 21 , 34 , 55  ...

5 is Fibonacci number since sum of its two previous number i.e. 2 and 3 is 5
8 is Fibonacci number since sum of its two previous number i.e. 3 and 5 is 8 and so on.

Question:Define Factorial. 

Factorial of number is defined as:
Factorial (n) = 1*2*3 … * n
For example: Factorial of 5 = 1*2*3*4*5 = 120
Note: Factorial of zero = 1

Question:What is Floyd’s triangle? 

Definition of floyd's triangle:
Floyd's triangle is a right angled-triangle using the natural numbers. Examples of floyd's triangle:Example 1:
1
2 3
4 5 6
7 8 9 10Example 2:
1
2   3
4   5   6
7   8   9   10
11  12  13  14  15
16  17  18  19  20 21

Question:Definition of LCM (Least common multiple): 

LCM of two integers is a smallest positive integer which is multiple of both integers that it is divisible by the both of the numbers.
For example: LCM of two integers 2 and 5 is 10 since 10 is the smallest positive numbers which is divisible by both 2 and 5.

Question:Definition of HCF (Highest common factor): 

HFC is also called greatest common divisor (gcd). HCF of two numbers is a largest positive numbers which can divide both numbers without any remainder.  For example HCF of two numbers 4 and 8 is 2 since 2 is the largest positive number which can dived 4 as well as 8 without a remainder.